Object: Practice with asynchrous I/O.
Create a directory named ``pup5'' under your home directory.
This directory must contain
- Makefile
- README
- other files..
When type ``make'' in your exercise directory, an executable named emit is created.
The file ``README'' contains your description of your exercise.
Due day, 5/7 00:01am
Description of "emit"
- Usage: emit n [f1] [f2]
  The ''emit'' program reads characters from stdin and write them out to stderr in the rate of n characters per second. If f1 and f2 are present, this program also writes characters to f1 and f2 with asynchrous I/O.
- How to test:
  First create two fifos, for example, f1 and f2.
  In the first shell, type
```
 $ ./emit 30 f1 f2 < some-test-file 
```
  In the second shell, type
```
 $ ./emit 5 < f1 
```
  In the third shell, type
```
 $ ./emit 15 < f2 
```
  It is important that the rate in 2nd and 3rd emit is slower than the one for 1st emit so that we can simulate the asynchrous I/O.